1. Area of the Invention
The present invention relates generally to orthopedics and more particularly to a multi-centric hinge joint for use in knee braces.
2. Prior Art
Hinge joints that operate to support or assist injured or infirmed body limbs are known in the art. Such devices typically comprise a pair of relatively moveable support members attached respectively to different parts of the body, for example, the upper and lower leg. In addition, some form of articulation means provides a resilient or other controlled or controllable interconnection between the proximal and distal members of the support device.
It is desirable for a hinge joint to provide control of an upper limb relative to a lower limb. Further, it is desirable for hinge joints to support and assist in the effective functioning of the limb, allowing the limb to attain certain limited degrees of motion and flexibility in predetermined directions in a manner that resembles normal body movement.
U.S. Pat. No. 5,328,446 (to Bunnell et al.) teaches a joint device that includes two extending sidearms, each sidearm secured by a sleeve, cast or brace to the patient's limb so that the sidearms are on opposite sides of the afflicted joint. The joint device pivotally connects the two sidearms and includes a selectively actuated one-way clutch which allows movement in one direction while inhibiting it in the other.
U.S. Pat. No. 6,027,466 (to Diefenbacher et al.) teaches an orthopedic joint for connection between first and second body parts for movement in a flexion/extension plane between adjustable stops.
U.S. Pat. No. 6,039,709 (to Bzoch) teaches a pair of opposed exterior plates containing slots for receiving an adjustment wheel threaded to a screw positioned in close association with gear teeth juxtaposed to the second end portion of a first elongated bar. The exterior plates enclose the second end of two elongated bars. The exterior plates are locked together with rivets to hold the gear teeth in position and permit movement or locking of the second elongated bar by manipulation of the adjustment wheel.
U.S. Pat. No. 7,189,212 (to Popp et al.) teaches a hinge for orthopedic braces which includes a pair of support arms, a pair of pivot pins and a hinge plate. The arms are coupled to the hinge plate through the pivot pins and are rotatable between an extension position and a flexion position. The hinge plate has a plurality of adjustment apertures for selective reception of an extension limit pin and a flexion limit pin to selectively restrain rotation of the arms beyond an extension limit and a flexion limit. The pins are retained on the hinge by flexible retainers and are individually positioned among the apertures to adjust the range of motion of the arms.
Hinge joints for knee braces in the prior art are bulky, heavy and difficult to adjust. They may make use of a wheel with gear teeth, a pawl and ratchet or other means that may fail to provide a user with the smooth sliding action of an uninjured knee.
Thus, there remains a need for a hinge joint that will provide versatility of motion that is simple, adjustable and unobtrusive and operates in a manner that mimics the anatomical motion of a knee.